There exist myriad of muscle strenghtening exercises involving the manipulation of weight-bearing apparatus including barbells. Among the most popular and effective exercises for the strengthening of the legs and/or lower back are squat exercises, deadlifts and lunges. The weight-bearing barbells and barbell supporting rack systems are typically designed without significant variation in their dimensions. Thus, the equipment utilized in these exercises presents unique challenges to individuals whose physical dimensions encumber their performance possibly resulting in injury. Thus, there is a need for improved methods and apparatus to accommodate individuals that would otherwise be hindered or potentially injured in the performance of such exercises.